arXiv:2605. 04568v3 Announce Type: replace-cross Abstract: State-of-the-art model-based Reinforcement Learning (RL) approaches either use gradient-free, population-based methods for planning, learned policy networks, or a combination of policy networks and planning.
By Jonathan Spieler, Sven Behnke
The paper introduces Multi‑Fidelity Policy Gradient (MFPG) methods that combine scarce, high‑fidelity (HF) reinforcement‑learning data with abundant, low‑fidelity (LF) data to stabilize training. Unlike prior approaches that directly optimize biased LF objectives, MFPG uses LF data only to construct a control variate that reduces variance without biasing the policy gradient. The authors extend MFPG to modern actor‑critic algorithms, notably a budget‑aware MFPG‑PPO that preserves cross‑fidelity correlation, monitors estimator uncertainty, and allocates a fixed sampling budget between HF and LF sources. Experiments on simulated robot locomotion and a physical Franka arm show that MFPG‑PPO consistently outperforms standard PPO trained on HF data alone and matches performance achieved with 16× more HF data on the hardest tasks, while enabling stable learning with as few as four real‑robot episodes per update.
By Xinjie Liu, Ruihan Zhao, Anirban Chaudhuri, Cyrus Neary, Ufuk Topcu, David Fridovich-Keil
arXiv:2607. 18830v1 Announce Type: cross Abstract: Model-Agnostic Meta-Learning (MAML) is a widely used framework for reinforcement learning (RL) that enables efficient transfer by learning global policy parameters that can be rapidly adapted to new tasks.
By Garvit Singla, Uma Maheswari Natarajan, Raghuram Bharadwaj Diddigi
arXiv:2510. 17709v2 Announce Type: replace-cross Abstract: Training Reinforcement Learning (RL) policies using simulation models before deployment in real-world environments is a common strategy when real-world interaction is expensive.
By Akhil S Anand, Shambhuraj Sawant, Paavo Parmas, Jasper Hoffmann, Dirk Reinhardt, Sebastien Gros
arXiv:2605. 20256v2 Announce Type: replace Abstract: Reinforcement learning has become a cornerstone for aligning and unlocking the reasoning capabilities of large-scale models.
By Xikai Zhang, Yongzhi Li, Likang Xiao, Yingze Zhang, Yanhua Cheng, Quan Chen, Peng Jiang, Wenjun Wu, Liu Liu
arXiv:2608. 02951v1 Announce Type: cross Abstract: Preference-based reinforcement learning (PbRL) for general stochastic MDPs often requires training a reward model.
By Evan Assmus, Qining Zhang, Lei Ying